Anzar Khan 교수

We demonstrate high efficiency and simplicity of the thiol-epoxy reaction towards preparation of a wide range of main-chain as well as end-chain multifunctional polymers.

Know where to fold 'em: A foldamer exhibiting a light-induced helix–coil transition (see scheme) can be constructed by introducing a photochromic azobenzene moiety (red) into the center of an amphiphilic phenylene ethynylene backbone (blue). This system gives insight into folding and unfolding mechanisms and promises applications in photoresponsive (bio)materials and “smart” delivery devices based on photoresponsive dynamic receptors.

Single and multiple post-polymerization modifications of poly(glycidyl methacrylate) scaffold through the nucleophilic ring-opening reactions of the pendent epoxide groups are described.

ABSTRACT Base‐catalyzed reaction between a thiol and an epoxide group is a simple fusion process that leads to the formation of a β‐hydroxythio‐ether linkage. This reaction is efficient, regio‐selective, and fast. In addition, it produces a reactive hydroxyl group upon completion. Therefore, it is of considerable potential in synthesis of reactive and functional soft materials. Here, we discuss the fundamental aspects of this process, the so‐called thiol‐epoxy “click” reaction, and its utility i

The thiol–epoxy ‘click’ process is employed as a polymerization reaction to prepare linear polymer chains substituted with free hydroxyl groups. Post-polymerization modification of the hydroxyl units afforded functional polymers exhibiting substituent dependent properties. In this way, functionalized macromolecules are obtained in two simple synthetic steps from commercially available monomer building blocks and reagents.

Introduction of photochromic azobenzene units into amphiphilic oligo(meta-phenylene ethynylene)s allowed photocontrol over the helix-coil transition in this important class of foldamers. Two design principles were followed in efforts to accommodate cis- and trans-azobenzene moieties within the helical structure to selectively turn the helical state on and off, respectively. Several oligomer series with varying connectivities to the central azobenzene chromophore were synthesized and these photoc

In this study, we probe various aspects of a post-polymerization double-modification strategy involving sequential thiol–epoxy and esterification reactions for the preparation of dual-functional homopolymers.

A novel and modular strategy has been developed for the preparation of reactive and functionalized hydrogels. In this strategy, thiol-epoxy coupling chemistry was employed for the formation of a hydrophilic network. The hydroxyl groups, generated during the coupling process, were then engaged in anchoring a fluorescent probe to the hydrogel scaffold.

The growing synergy between supramolecular chemistry and polymer synthesis is driven by the realization that the dynamic nature of non-covalent interactions may bring new properties and material performance to the field of polymer science. This is manifested in the area of block copolymer self-assembly where supramolecular systems have displayed remarkable morphologies and properties not attained in classic covalent systems. This review article examines the broad strategy of combining phase sepa

Aggregation of poly(para-phenyleneethynylene)s is efficiently suppressed by introduction of branched oligoethyleneglycol side chains rendering the polymer backbone, which is readily obtained using an A2 + BB' polycondensation protocol, soluble and highly emissive in aqueous environments.

ABSTRACT A synthetic route is developed for the preparation of an AB‐type of monomer carrying an epoxy and a thiol group. Base‐catalyzed thiol‐epoxy polymerization of this monomer gave rise to poly(β‐hydroxythio‐ether)s. A systematic variation in the reaction conditions suggested that tetrabutyl ammonium fluoride, lithium hydroxide, and 1,8‐diazabicycloundecene (DBU) were good polymerization catalysts. Triethylamine, in contrast, required higher temperatures and excess amounts to yield polymers.

We report polyethylene glycol-based reactive diblock copolymer as well as random copolymer scaffolds that can be transformed into desired bifunctional copolymers in two synthetic steps. Synthesis of the general scaffolds is achieved via a controlled atom transfer radical polymerization process while the functional groups are introduced via thiol–epoxy ‘click’ and esterification reactions.

By combining ATRP polymerization with thiol–epoxy ‘click’ chemistry, a general, efficient, and protection/deprotection-free route is developed for the preparation of chain-end multifunctional polymers.

Proton-transfer photopolymerization through the thiol-epoxy "click" reaction is shown to be a versatile new method for the fabrication of micro- and nanosized polymeric patterns. In this approach, complexation of a guanidine base, diazabicycloundecene (DBU), with benzoylphenylpropionic acid (ketoprofen) generates a photolabile salt. Under illumination at a wavelength of 365 nm, the salt undergoes a photodecarboxylation reaction to release DBU as a base. The base-catalyzed ring opening reaction t